Table 1.

Overview of available vitamin D preparations, their characteristics, typical indication, side effects and costs. CKD (chronic kidney disease).

	typical daily dose	indication and side effects	costs
NATIVE vitamin D
unhydroxylated, inactive from of vitamin D3 cholecalciferol calciol	400–4000 IU (max 10,000 IU)	vitamin D deficiency, osteoporosis therapy and prevention, hypoparathyroidism, prevention of rickets [27] hypercalcemia (rare)	inexpensive
unhydroxylated, inactive form of vitamin D2 ergocalciferol vitamin D2	400–4000 IU (max 10,000 IU)		inexpensive
ACTIVE vitamin D
hydroxylated, active form of vitamin D 1,25(OH)2D calcitriol 1,25-dihydroxyvitamin D3, 1,25-dihydroxycholecalciferol analog: alfacalcidol	0.25–1.0 μg	secondary hyperparathyroidism in advanced CKD [35], hypoparathyroidism [36,37], pseudohypoparathyroidism [38], not in vitamin D deficiency hypercalcemia/hyperphosphatemia is not uncommon (dose dependent), hypercalciuria, nephrocalcinosis	expensive
other active vitamin D analogs: paricalcitol, doxercalciferol (vitamin D2 analogs) falecalcitriol, maxacalcitol (vitamin D3 analogs)		secondary hyperparathyroidism in advanced CKD hypercalcemia may occur, but less frequent compared with “older” active analogs	very expensive